This circuit with two HT2030s powers 6 LEDs in a decorative flashing system. The circuit is from Electronics Now magazine, December 1997. The LEDs are fed in sequence.
This interesting circuit measures the distortion of the sinusoidal voltage of the power grid. We...
The operational amplifier used in this old application is not common today, but more modern...
Used in 1950s CW receivers, this type of circuit used germanium transistors. The circuit has...